1. Field of the Invention
The present invention relates to a sewage disposal apparatus and a prefabricated structure for accommodating the same. The raw sewage disposal apparatus can be utilized in the outdoors, in a transportation vehicle such as a vessel or train, or in a tunnel through which a tank truck used for collecting raw sewage (hereinafter referred to as a vacuum truck) cannot go and, more particularly to such an apparatus which is capable of cleaning a stool by urine which is temporarily stored in a urine tank. The prefabricated structure can be conveyed by the vacuum truck. The prefabricated structure has a hoist mechanism, which mechanism is utilized to load the prefabricated structure on the bed of the truck from the temporary site or unload the prefabricated structure from the bed of the truck to the temporary site.
2. Description of the Prior Art
The raw sewage discharged from human bodies is typically discharged into a sewage system by use of a flush toilet or the like and then flows into a river after being temporarily stored in a holding tank and purified therein. However, at events such as festivals, athletic events, fairs, meetings and the like, temporary toilet facilities must be provided to dispose of raw human waste.
Employed conventionally are movable temporary toilets, most of which have a tank for temporarily storing the raw sewage therein. However, the temporary toilets have the problem that the raw sewage stored in the tank must be sucked into a vacuum truck for collection, which is laborious and time consuming, for maintenance thereof after use of them, and is unhygienic.
Transportation vehicles, such as busses, trains, vessels, etc., which operate over long distance are provided with a tank exclusively used for storing and holding the discharged raw sewage. The raw sewage in this tank is subjected to a deodorizing treatment by chemicals and thereafter is collected by the vacuum truck.
As mentioned above, the raw sewage in conventional temporary toilets or movable transportation facilities is stored as it is discharged from the human body and is collected thereafter. Accordingly, the storing method, the collection method and the disposal method all are not modern and are very unhygienic.
In an attempt to ameliorate the above problems, there have been proposed several hygienic disposal methods. In one method, for example, chemicals are introduced into the tank where the raw sewage is stored to thereby prevent the bad smell and to effect sterilization of the sewage. This method, however, cannot be used for a long period of time because the chemicals become diluted and costs are high.
In another method, the raw sewage is stored in a bag made of vinyl and the like to prevent the diffusion of the bad smell. This method, however, requires a vinyl bag of large size and involves a high cost for disposal thereof, and it is troublesome to separate the raw sewage from the bag.
In still another method, the discharged raw sewage is directly dried by use of heat from a burner, etc. Since the primary component of raw sewage is liquid, a large amount of heat energy is required to remove the liquid and it takes a long time to effect disposal of the raw sewage.
In view of the drawbacks of the conventional methods of disposing of the raw sewage, the present inventor proposed a disposing apparatus having a casing provided with stirring blades and heat holding bodies therein in which the raw sewage is stirred by the rotation of the stirring blades and heated by heat generated by the heat holding bodies whereby the raw sewage is dried in a short period of time as disclosed in Japanese Patent Laid-Open Publication Nos. 63-124150, 63-172852, 63-190857, 63-292789 and Application No. 63-198858, and U.S. Pat. No. 4,999,930. According to the proposed disposal methods, the raw sewage is heated, vaporized in a casing and the liquid component of the raw sewage is vaporized and diffused into the ambient atmosphere. Before the liquid component is diffused, the components which cause a bad smell are resolved by a catalyst so that the vapor is diffused into the atmosphere as an odorless vapor. It was preferable to employ such a method in view of environmental hygiene and preservation even if such method is employed in crowded buildings and/or by throngs of people.
Another related U.S. application is Ser. No. 575,910, filed Aug. 29, 1990.
It is hygienic to evaporate and dry the raw sewage contained in the airtight tank and such operations can be carried out systematically, which results in not causing a burden to the operators. However, the conventional raw sewage disposal apparatus includes a stool which is connected thereto and filth is liable to attach to the stool after long term use of the stool, which makes the temporary toilet unsightly. Under the circumstance, it is preferable to clean the stool every time the user uses the stool. Conventionally, the water stored in the stool is jetted so that the filth attached to the stool is forcibly removed. The water which was used for cleaning the stool is evaporated together with the raw sewage. With such an arrangement, an exclusive water tank should be provided in the raw sewage disposal apparatus, which makes the structure of the temporary toilet complex and makes the maintenance of the water tank troublesome because the water should be supplied regularly into the water tank.
To meet the demand, the present inventor proposed a recycling type disposal apparatus which is disclosed in Japanese Patent Application No. 2-164594. According to this apparatus, the vapor evaporated in the evaporation cauldron is condensed and stored in another tank. The condensed water is used for flushing. With the arrangement of this apparatus, if a given amount of water is poured, at the early stage of the use, into a water tank, the water cleans the stool and is introduced into the evaporation cauldron and evaporated. The evaporated water is condensed and collected into the water tank, and hence the water can be circulated and used semipermanently. If the exclusive flushing water is used for cleaning the stool, not only the flushing water but also the water for flushing the raw sewage collects in the evaporation cauldron and another is evaporated at the same time, which takes much time for evaporation and much energy is wasted uselessly. In view of the above circumstance, a raw sewage disposal apparatus, which saves the energy and always keeps the stool clean, is desired.
Referring to the prefabricated structure for accommodating the raw sewage disposal apparatus, the conventional temporary house has been installed at temporary sites such as rivers beds, building construction sites, mountains, and used also at offices, lodges, warehouses, etc. Such movable temporary house is assembled and then loaded on the bed of the truck. The temporary house is conveyed by the truck to the temporary site where it is installed. Although the large temporary house having a large capacity and large floor area can not be loaded on the bed of the truck, the temporary house having relatively small floor area is assembled individually and conveyed by the truck and utilized as the temporary toilet. Accordingly, such small temporary house is stored at a warehouse or yard as it is assembled, and is conveyed and used as it is assembled.
Such small temporary house is loaded on the bed of the truck, and conveyed to the temporary site where it is utilized for its purpose. When the temporary house, which is normally kept at the warehouse or yard, is loaded on the bed of the truck, a forklift truck is required. However, the forklift truck is often not available at the temporary site. Accordingly, the temporary house must be unloaded from the bed of the truck by manpower in many cases. Since such temporary toilet is often provided with a cooler, a luminaire, a locker, etc., it is difficult to manually load it on or unload it from the bed of the truck. Thus, the forklift truck should be moved to the temporary site, which is often inconvenient.
The truck provided with a crane is nowadays utilized in many cases. The loading and unloading operation can then be accomplished with ease utilizing such crane. However, if the temporary house is lifted using a wire sling, the wire contacts the side surfaces of the temporary house, which deforms or damages the wall surfaces. Accordingly, the loading and unloading operation using the wire sling should be carried out carefully, which takes time and is troublesome. It is very convenient if the temporary toilet can be lifted by the crane of the truck without damaging the temporary toilet.